Craig, I read your message, do you really need to be working at the Grib level? You could be working at a higher level( CDM ) layer and still get data values for a variable. Also, you would be removed from the details of the grib that you mention in your message. What do you want for a end result? Could you provide a test file so I could provide an example program on how to work at the CDM layer. Robb... Ticket Details =================== Ticket ID: JNJ-582161 Department: Support netCDF Decoders Priority: Normal Status: Open